Brother of SaintMethodius. Born to the Greek nobility; his family was connected with the senate of Thessalonica, and his mother Maria may have been Slavic. Studied at the University of Constantinople, and taughtphilosophy there. Deacon. Priest. Librarian at the church of Santa Sophia. Monk, taking the name Cyril. Sent with Methodius by the emperor in 861 to convert the Jewish Khazars of Russia, a mission that was successful, and which allowed him to learn the Khazar’s language. In 863, sent with Methodius to convertMoravians in their native tongue. Though some western clergy opposed their efforts and refused to ordain their candidates for the priesthood, they did good work. Developed an alphabet for the Slavonic language that eventually became what is known today as the Cyrillic. After initial criticism for their use of it, the brothers achieved approval of the Liturgy in the Slavonic language. May have been bishop, but may have died before the consecration ceremony.

When the time came for Cyril to set out from this world to the peace of his heavenly homeland, he prayed to God with his hands outstretched and his eyes filled with tears: “O Lord, my God, you have created the choirs of angels and spiritual powers; you have stretched forth the heavens and established the earth, creating all that exists from nothing. You hear those who obey your will and keep your commands in holy fear. Hear my prayer and protect your faithful people, for you have established me as their unsuitable and unworthy servant. “Make your people known for the unit and profession of their faith. Inspire the hearts of your people with your word and your teaching. You called us to preach the Gospel of your Christ and to encourage them to lives and works pleasing to you. “I now return to you, your people, your gift to me. Direct them with your powerful right hand, and protect them under the shadow of your wings. May all praise and glorify your name, the Father, Son, and Holy Spirit. Amen. – from an old Slavonic biography of Saint Cyril